Gitlab JWT

I am trying to use jwt as a third party authentication on my private gitlab

  1. I registered a service in rapid connect:

  2. I configed gitlab.rb

  3. reconfig & restart

  4. going to my private gitlab:

    jtw option showed up, but after I clicked it, it will redirect me to which I declared in step 1, obviously, this page doesnt exist, so 404 came up
    I think I should redirect the user to the page where the jwt token gets processed, so could someone tell me which page is responsible for this task?